Art of treating hydrocarbons



UNITED srArns Parana." orrror..

JOHN W. COAST, JR., OF TULSA, OKLAHOMA, ASSIGNOR TO TH PROCESS COMPANY, A V

CORPORATION OF MARYLAND.

Application filed May 5, 1917.

'To all whom. 'it may concern: f

Be it known that I, JOHN W. Cons'r, Jr.7 a citizen of the United States of America, a resident of Tulsa, in the county of Tulsa, State of Oklahoma, have invented certain new and useful Improvements in the Art of Treating Hydrocarbons, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings. forming a part of this specification.

My invention relates to improvements in the art of treating hydrocarbons, and more particularly to a method of cooling hydrocarbon vapor and at the same time heating albody of liquid. The new method may be followed in cracking petroleum hydrocarbons under pressure, to obtain a vproduct known as gasolene, or cracked gasolene. In cracking such hydrocarbons, the vaporize fractions having relatively high boiling points should be condensed and returned to the still for further treatment, and the fresh charge of oil should be heated before it reaches the still. One of the objects of my invention is topprovide a simple' and efficient method of accomplishing these results.

In the Vpreferred form of the invention, a body of relatively cool liquid is maintaine in a heat exchanger, and the hot vapor passing from the still is discharged into this liquid. The hot vapor is permitted to rise in the form of bubbles in the relatively cool liquid,V thereby heating the liquid and at the same time condensing the previously vaporized fractions having relatively high boiling points. The body of liquid maintained in the heat exchanger may be formed partly by the high boiling` point condensate, and partly by a fresh charge of oil. In this event, the hot condensate will serve as a heating medium for the fresh charge of oil, and the liquid mixture will be constantly subjected to the heat of the vapor which bubbles through the liquid. Some of the liquid will be converted into vapor and pass to a condenser. The heated liquid preferably overflows and passes 'to the still. Some of this overflowing liquid is condensate formed by condensing the high boiling point fractions, and some of it is preferably a fresh charge of oil which hasbeen sub- -jectedto the heat of the vapor and condensate.

Specification of Letters Patent.

-At'this point the numerous Patented Mai-.16,192o.

Serial No. 166,524.

The drawing is a diagrammatical view of an apparatus adapted for use in carrying out my method.

To illustrate vthe invention, I have shown a cracking apparatus comprising a pressure still 1 arranged above a heating chamber 2, a vapor pipe 3 leading from. the still to a heat exchanger A, a Vapor pipe 4 connecting the heat exchanger to an air cooled reflux condenser 5, and a vapor pipe 6 connecting said reflux condenser to a cooled condenser 7, from which the product is recovered. A pressure regulating valve 8, in the vapor pipe 6, may be regulated to maintain a predetermined pressure in the reflux condenser, heat exchanger A, and also in the still 1. A perforated discharge member 9, connected to the vapor pipe 3l is submerged ina relatively cool body of hydrocarbon liquid contained in a reservoir 10. These members 9 and 10 form part of the heat exchanger A. An overflow pipe 11, provided with a liquid seal, or trap, 12, leads from the'surface of the 4liquid in the reservoir 10 to the lower portion of the still 1. A pump 13 may be used to force a fresh charge of relatively cool hydrocar bon oil through a pipe 14 and into the reservoir 10.

The new method may be followed in cracking various heavy hydrocarbon products resulting from petroleum, drocarbons having boiling points higher than 350 F., the most beneficial'results being obtained `from hydrocarbons having boiling points ranging from 450O F. to 700 F. The valve 8 in the vapor pipe 6 is adjusted to obtain the desired pressure in the still, heat exchanger A and reflux condenser The pressure may range from 50 to 150 pounds per square inch, or veven higher, but it is preferably maintained at about 85 pounds per square inch. The contents of the still are preferably subjected to such a high degree ofheat that the hydrocarbon liquid will vaporize very rapidly. This .temperature may range from about 600o F.

to 8000 F.. and is preferably about 725 F. "Owing to the intense heat and the rapid iaporization` a large volume ofunconverted, or partially converted, hydrocarbons will .flow from the still 1 to the heat exchanger A. small streams of .WaterIk the treatment of crude particularly 'such inexpensive hy-' vapor discharged from the submerged perforated member 9, rise in the form of bubbles in the relatively cool hydrocarbon liquid, thereby heating said liquid, and at the same time condensing the previously vaporized fractions having relatively high boiling points. By bubbling the vapor through a relatively cool liquid, as herein shown, all of the yvapor is very effectively subjected to the action of the cool liquid, and the heaviest fractions are condensed and prevented from passing to the main condenser. 'YThe heat exchanger therefore constitutes a highly efficient condenser for the high boiling point fractions. The hottest portion of the liquid overflows from the heat exchanger and passes through the overflow pipe 11 to the still l.

The fresh charge of relatively cool oil, flowing from the pipe 14, commingles with the hot condensate inthe heat exchanger A,

and is also subjected to the high temperature of the hot vapors bubbling through the liquid mixture in the heat exchanger. The fresh chargeof oil is thus subjected to a very high temperature, and thoroughly heated,

before it overflows at the surface of the liquid body in the heat exchanger. l

The reflux condensate, flowing from the condenser 5, passes through the pipe 4 and commingles with the liquid in the heat exchanger, this condensate being heated before it overflows to the still.

The desirable low boiling point fractions flow from the reflux condenser 5, through the vapor pipe 6, and vinto the main condenser 7, where they are condensed to form the low boiling point product.

It will now be understood that the hot vapor, bubbling through the hydrocarbon liquid inthe heat exchanger, is cooled 'so as to separate the high boiling point fractions from the lighter fractions; the hot condensate returns freely to the still; the fresh charge of oil is thoroughly heated by the vapor and also by the hot condensate; the heat exchanger also serves as means for heating the reflux condensate flowing from the condenser 5, and although the vapor is bubbled through the liquid, it will heapparent that the heat exchanger will perform its several functions while maintained under the high pressure which must necessarilybe employed in cracking petroleum hydrocarbons.

Iclainiz-g l. In the art of treating petroleum hydrocarbons, the method which comprises maintaining a body of hydrocarbon liquid in a 'leser-voir, vaporizing and cracking hydrocarbon liquid in a still, conducting vapor from the still andl discharging it into said said reservoir, permitting the heated condensate to overflow from said reservoir, and

conducting the overflowing condensate into said still.

2. In the art of cracking petroleum hydrocarbons, the method which comprises maintaining al body of relatively cool liquid in a reservoir, vaporizing and cracking hydrocarbon liquid in a still, conducting vapor from the still, dividing the vapor into numerous small streams and ,at the same ytime discharging the streams of hot vapor into said body of relatively cool liquid at points below the surface thereof, permitting the numerous streams of hot vapor to rise freely in the form of bubbles in the relatively cool liquid in said reservoir, thereby heating the last mentioned liquid and at the same time condensing high boiling peintl fractions in the vapor, conducting vapor from the surface of the liquid in said reservoir and through a reflux condenser to a main condenser, returning high boiling. point condensate from said reflux condenser to said reservoir, so as to subject such condensate to the streams of hot vapor bubbling through said reservoir, ermitting the heated `condensate to ove 0W from said reservoir, conducting the overflowing condensate into said still, and maintaining said still and reservoir under a pressure greater than 50 pounds per square inch. In testimony that I claim the foregoing I hereunto affix my signature.

JOHN w. ooAs'r, JR. 

